Diffraction-limited images can now be obtained from the ground using
adaptive optics. We present here a number of results obtained with
this technique by researchers at the Institute for Astronomy.
These include:
1) Observations of the rings of Saturn as the Earth was crossing the
ring plane in August 95. Evidence was found for a dozen of 20- to 40-km
diameter objects, probably clumps, orbiting at the distance of
the F-ring. Among these objects two of them have been identified
with objects 1995 S5 and S7 observed by the Hubble Space Telescope.
An eclipse of Epimetheus by the F ring was observed, putting new
constraints on its orbit as well as the size and density of the F ring.
Photometric profiles have been obtained along the rings, and their time
evolution has been modeled.
2) Observations of Titan through narrowband filters in and out of
the 1.6 micron methane window. The surface feature observed by Smith
et al and Combes et al on the leading hemisphere has been detected
as well, albeit with morphological differences. A program of
adaptive-optics observations of Titan is under way.
3) K-band observations of Uranus and its rings. Puck has been detected.
4) K-band observations of Neptune, confirming that low-latitude cloud
activity has shifted from the south to the north hemisphere since
Voyager observations. For the first time Proteus was detected from
Earth and its albedo was measured at 2.2 m.
5) Wide band observations of Pluto and Charon. A program of narrow band
photometry of the individual components is under way.
6) Observations of asteroid 4 Vesta during its 1996 opposition through
narrow band filters in and out the pyroxene bands. Its dimensions and
shape as well as the nature of the geological units present on its
surface, have been derived.